The applicant's earlier patent specification WO 2008/110832 discloses a party balloon, that is to say a toy balloon, having an illumination device mounted inside, the illumination device comprising a light emitting diode (LED) powered by at least one battery. The LED lights up when a strip of insulating material is withdrawn from between the battery and the LED to complete the circuit and the balloon is thereby illuminated from its interior.
In other versions of illuminated balloon, a switch may be provided which can be manually actuated to connect or disconnect a light source from its power source thereby selectively to illuminate the balloon cavity.
In the applicant's known party balloon the illumination device is mounted to the inside of the balloon wall by having a projection which is engaged from outside the balloon by an attachment element, such as a clip or a band, more specifically an O-ring of elastic material. Projections in the form of a partially spherical button or, more preferably a flattened button, were proposed.
Although the applicant's earlier specification is primarily concerned with a balloon formed in one piece of elastomeric material, such as latex, the manner of mounting the illumination device inside the wall by means of a projection engaged from outside by a clip or band or similar is also applicable to a balloon formed from two sheets of flexible material connected around their edges, the sheeting being formed of substantially inelastic material, such as metallised plastics material or Mylar.
However, other means of mounting an illumination device to the wall of a balloon are possible. For example the device may be attached by adhesive when the balloon wall material is of the substantially inelastic type.
Typically it is intended that the illumination device should only operate once the balloon is inflated so as to light up the inflated balloon.
In the event that the balloon bursts when inflated, the illumination device which has been mounted inside may be flung out at some speed.